A recent study by Dalhousie University in Canada showed that if greenhouse gas emissions continue at current levels, nearly 90 percent of all marine species could be threatened with extinction by the end of the century. Among the various species of animals, plants, chromis, bacteria and protozoa studied in the study, species with higher trophic levels, especially those that are taken for food, including tuna, sharks or pufferfish, have the highest risk of extinction.
The researchers assessed the threats faced by the nearly 25,000 marine species living in the top 100 meters of the ocean if greenhouse gas emissions remain high, under a “business as usual” scenario.
The analysis showed that almost 90 percent of these animals could be at high or critical risk of extinction by 2100, and could not survive in their current habitat in an average of 85 percent of their geographic distribution. In addition, scientists have found that about 10 percent of the ocean contains zones where high climate risk and endemism (a condition where a species occurs in one specific geographic location) combine, posing additional threats to the vast majority of ecosystems.
According to study lead author Daniel Boyce, an environmentalist at Dalhousie University, the findings are “quite striking and very sobering,” providing clear evidence of the grave danger to life on our planet if fossil fuel extraction continues unabated.
“I’d like to think that’s an implausible scenario,” he said. “But still, this is the worst-case scenario. And when we assessed this scenario, we found that there is a very bleak picture of climate risk for marine species.”
The threat has been found to be greater for many of the species currently harvested for food in low-income countries heavily dependent on fisheries. “A really striking pattern was found where the risk was systematically increased for countries of lower socioeconomic status, low-income countries that tend to be more dependent on fisheries and tend to have lower food security and overall nutritional levels. ‘ said Professor Boyd.
These findings should lead to increased efforts to prioritize the conservation of vulnerable ecosystems by incorporating the receptivity and adaptability of various species into climate management strategies. “This should be a strong motivation for us to do our best to reduce emissions and focus on avoiding the worst-case scenario,” he concluded.
The study was published in the journal Nature Climate Change.